-----Original Message-----
From: r-help-bounces at r-project.org
[mailto:r-help-bounces at r-project.org] On Behalf Of Corey Sparks
Sent: Wednesday, February 25, 2009 11:50 AM
To: R Help
Subject: [R] Using gregexpr with multiple search elements
Dear list,
I am trying to use gregexpr to see if entries in a dataframe
have either of two possible values for a string.
here's an example
text<-c("fat", "rat", "cat", "dog", "log", "fish")
If I just wanted to find if any one of the elements in text
match the pattern "at" I would do gregexpr("\\at", text)
which would match on the first three elements, you can do
something like ifelse(gregexpr("\\at",text)>-1, 1,0)
to see if a particular entry in the data "text" is matched.
My problem is I need to check if either of two patterns match
in the data, an example that doesn't work is
gregexpr(c("\\at", "\\og"), text)
which is the basic form of what I'm looking to do, if this
would work I would get a match for elements 1 through 5 of
text, since either "at" or "og" occurs.
If anyone might have an idea about this I would greatly appreciate it.
Best,
Corey
Corey Sparks
Assistant Professor
Department of Demography and Organization Studies University
of Texas at San Antonio One UTSA Circle San Antonio, TX 78249
210 458 6858 corey.sparks at utsa.edu